If you've ever noticed that most relationships go through a brief period of intense sexual attraction that eventually morphs into intimate cuddling sessions, you may have been observing a couple'sÂ loss of neutrophins without actually knowing it. Scientists have discovered that these hormones are responsible for making new partners feeling sexually attractive to one another, but they only stick around for a maximum of two years.

After the neutrophins wear off, they are replaced by oxytocins, a.k.a. "the cuddle hormone." These hormones make couples feel intimate and can help the relationship last, sans the sexual desires that existed at its start. The most important aspect of this discovery is whether or not scientists could help make the neutrophins last longer—effectively bringing sexy back to these cuddly relationships.